Motor-compressor unit for refrigerating apparatus



Nov. 30, 1937. c. E, L. LIPMAN 2,100,716

MOTOR COMPRESSOR UNIT FOR REFRIGERATING APPARATUS Filed April 3., 1935'2 Sheets-Sheet? Patented Nov. 30,1937

MOTOR-COMPRESSOR UNET FR REFRG- ERATING APPARATUS Carl E. L. Lipman,Chicago, lili., assigner to Lipman Patents Corporation, Chicago, 1li., acorporation of Delaware Application April 3, 193e, seriali Ne. ecarte 11claims.

This invention relates generally to refrigerating apparatus particularlyadaptable for house-- hold refrigeration, although it will be manifestthat many of the novel features of my invention are capable or"embodimentin apparatus suitable for purposes other than that ofrefrigeration.

More specifically my invention relates to hermetically sealedrefrigerating units in which the lubricating oil is utilized tolubricate and cool the driving motor, a portion of the oil at leastbeing cooled to remove the heat units absorbed therein.

An object of my invention is to provide means automatically operable tocontrol the cooling of the oil in such a Ymanner as to maintain orquickly restore a proper working temperature of the unit which will,prevent overheating of the motor, and alsoprevent undue absorption ofrefrigerant in the oil. Another object is to improve the motorconstruction so as to facilitate the absorption of heat units therefromby the circulating oil and thereby increase. the life and efficiency o f'the motor.

Other objects and inherent advantages of' invention will be appreciatedas the same become better understood froman examination'of thisspecification and claims in connection with.the accompanying drawingstherein.

Fig. 1 is a schematic view of a complete refrigerating apparatus withthe motor compressor unit-shown in section,

Fig. 2 is a fragmentary section of the base of the motor compressor unitwith the oil strainer removed, Y

Fig. 3 is a plan of the thermostatically controlled valve,

Fig. fi isa vertical central section through the thermostaticallycontrolled valve taken approxlmately along line I-Il of Fig. 3,

40 Fig. 5 is a vertical section through the therl mostaticallycontrolled valve taken approximately along line 5--5 of Fig. 4, Fig. 6is a fragmentary plan of the motorv stator, and

Fig. 7. is a fragmentary side elevation of the motor stator. f A

Referring now to the drawings in more detail, and particularly to thediagrammatic lay out shown in Fig. "l, reference character i indicates50 generally the hermetically sealed unit in which the operating parts,all in the apparatus to be fdescribed, aredisposed and into which thecompressor discharges the refrigerant compressed 55' thereby. Therefrigerating medium is delivered from the sealed casing' through a pipe2 to a condenser 1% cooled by fan 4 which may also circulate air throughthe unit l, if desired, from which the condensed refrigerant is conveyedby a pipe 5 to a float chamber 6, and thence through pipe 'l to anexpander or evaporator 8 from which the expanded refrigerant isconducted through pipe 9, check valve ll, and pipe l2 to the suctionside of the compressor.

It should be understood that While l have illustrated a conventionalflooded type of refrigerating system, including an evaporator, any othertype of system including an expansion valve or expander may be employedif the system is operated on some other principle than the floodedsystem principle.

The motor compressor unit shown 4in section (Fig. l) comprises generallya base i3 providing an annular oil sump and having a central table i4shaped to provide a central oil well l5 in the interior thereof. Thetable constitutes a support for a pump housinor comprising a disc orbase plate IB formed in the bottom of the housing, and an annular memberi'l forming the 'sidewalls of the housing and provided with a-jcentlal'bore constituting the rotor chamber. A

' tubular standard it having a bottom flange I9 which constitutes thetop plate of the rotor chamber-is seated upon the top of the annularmember Withwthe tubular standard rising upwardly therefro'm Upon theflange I9 an annular spider 2l is supported which carries the stator 22of the electric driving motor.

The standard yi8 serves as the journal bearing for both the rotor of theelectric driving motor and the shaft of the pump so that the rotor andcompressor or pump are coaxially disposed. A rdtor sleeve 23 carryingthe rotor structure 24 surrounds and is journalled upon the periphery ofstandard I8. The compressor rotor shaft 26 is formed integrally with thepump and compressor rotor 21, and is journalled within standard I8concentrically with sleeve 23. The upper portion of shaft 2B abovestandard I8 is squared to receive a driving disc 28 provided withradially projecting arms which engage in slots formed in the upper endof sleeve 23 whereby a direct but laterally adjustable drivingconnection between the rotor sleeve and the pump shaft is raccomplished.

The rotor of the pump and compressor is diS- posed eccentrically withinthe bore of the rotor housing and is provided with a plurality of'radially disposed blades 29 adapted to reciprocate radially in therotor. The blades are maintained `surface of the shaft to lubricate thelatter.

at all times-a predetermined distance apart by pin 3l extendingtransversely of the rotor between lthe blades. The length of theabutment pins is such that the outer ends of the blades which areprovided with sealing members 32 will always be maintained in contactwith the surrounding walls of the rotor housing. As one blade is forcedinwardly during rotation of the rotorfthe corresponding blade will beforced through the rotor'and against the opposite wall.

The gas to be compressed by the pump is admitted in the usual manner tothe cylindrical bore around the rotor before being connected thereto bysuction pipe l2. The admitted gas is compressed by the rotation of theblades and discharged through an outlet port, not shown, and finallydischarged into the interior of the sealed casing.

For lubricating and cooling the motor and compressor unit, I haveprovided a continuous lubricant circulation system in which thelubricant serves for lubricating the compressor and also sealing thesame, as well as to cool the stator and/or rotor of the driving motor.

It is understood, of course, that a sufficient amount of oil is placedin the unit and settles to the sump from which it is piped by conduit 33into an oil cooler orradiator 3d from which it is piped by conduit 35 tothe well l5 through a duct 31 formed in the base. Oil will be suckedinto the pump through a duct 3S extending from well l5 and leading tothe space between the inner ,ends of the blades and the outer peripheryof the pump rotor, the latter constituting the inlet for the oil pumpwhich, in the present instance, is the compressor, the inner ends of theblades being used for circulating the oil and the outer ends being usedfor compressing the refrigerant.

The oil is discharge-d under pressure from the pumpv partly through anoil port 39 communicating with a central bore fil formed in the lowerend of shaft 3G, which bore communicates with a spiral oil groove ft2formed in the periphrlal e upper end of spiral groove Q2 communicateswith a central bore 43 formed in the upper end of shaft 26 communicatingwith lateral ports dit which direct the oil outwardly upon a separatingand distributing disc i6 which separates what refrigerant vmight beincluded in the oil and throws the oil outwardly between an outer cap orshield (il and an inner cap or shield 48 which directs the oil over theperipheral margin of stator 22.

Another portion of the oil discharged by the pump passes upwardlythrough a duct 59 which communicates with an annular groove 5l formed inthe outer peripheral surface of standard I8 and which communicates witha spiral groove 52 which terminates at its upper end in a lateral duct53 which directs the oil outwardly beneath a cap or shield 54 carried bythe upper face of the motor rotor and which directs the oil downwardlythrough vertical apertures 56 formed in the rotor.

The stator is provided with vertical apertures 51 through which the oilpassing between caps 4l and i8 is directed.` The periphery of the statormay also be serrated or grooved as at 58 to provide additional channelsfor conducting oil in intimate contact with the stator whereby greatercooling veffect is obtained. The latter are particularly effective whenthe quantity of oil passing between caps 41 and 48 is too great to beconducted by apertures 51, which are quite small, and flows over theperipheral rim of cap 1&8. The latter condition is also likely to occurwhen the oil is quite cool and consequently fairly thick.

The oil owing through apertures 56 and 51 collects in the bottom ofspider 2l and passes out through a port 59 formed therein. The oilpassing over the outer periphery of the stator and through`channels 58is collected by an annular inclined trough 6l surrounding the spider andhaving its two ends terminating adjacent port 59.

To maintain the lubricating oil at a sufficiently high temperature toprevent absorption of refrigerant therein, the circulation of the oilthrough the cooling' radiator 313 is controlled. For this purpose duct31 is provided with a pair of side outlets 52 communicating with the oilsump in the casing. These ports are controlled by a thermostatic valveshown more particularly in Figs. 3, 4 and 5, and comprising a valve body63 secured over ports 62 having an interior chamber closed by a cap E4.The body is provided with a pair of side outlets or ports S8communicating with the sump in the casing, the ports being disposedbelow the normal oil level in the casing.

The ports are arranged to be sealed by a bimetallic closure member 6l inthe form of a ring secured at its mid point to a fixed abutment. 68 andhaving its end portions free to expand when the ring is heated toalpredetermined temperature to seal ports "66. The thermostatic valve isdisposed below port 59 and the ends of trough 6l so that the warm oildelivered over and through the stator and rotor of the electric motorwill be delivered upon the thermostatic valve. The screen 69 (Fig. l) issecured to and surrounds the thermostatic valve to strain the oil priorto its entering into the valve and thus prevents any foreign matter fromaffecting the operation of the valve. y

In operation the valve functions to permit warm oil to be circulatedfrom the sump through the pump and over the motor, that is, when the oilin the casing reaches a temperature suiciently low so that there isdanger of refrigerant being absorbed therein, the oil is by-passeddirectly.

from the motor through the thermostat valve to the suction side of thepump. When the oil reaches a temperature sufciently high so that thereis no danger of refrigerant being absorbed in detrimental amounts, valve6l closes ports 66 and the oil is circulated through the oil cooler Sli.

`It will be apparent that when valve 61 is open Av separate inlet port'Hl and duct 'Il (Figs. 2lv

and 5) is provided to permit warm oil being utilized for seal oil at alltimes, which oil comes in direct contact with the gas in the compressionchamber of the compressor. To assist in maintaining constant temperatureand completely insulating the motor compressor unit both as to heat andnoise, the unit is provided with an insulating cap 'l2 for the dome d?and an insulating cover 'I3 for the base. The` unit standsupon threearcuate feet 14.

From the foregoing description it will be apparent that I have not onlyprovided for circulation of the lubricating oil in a manner whichinsures intimate contact oithe oil in heat-absorbing relation to boththe stator and rotor but have also provided means for controlling orregulating the circulation of oil through the unit and oil cooler insuch a manner as to assure a substantially constant temperature in theunit to prevent absorption of the refrigerant in the lubricating oil.Other novel features and their resultant advantages will be apparent tothose skilled in the art, and to whom it will also be obvious thatchanges may be made in the details of construction without departingfrom the spirit and scope of this invention.

I claim:

1. An apparatus comprising a casing, a pump within said casing, anelectricrmotor within said casing, a driving connection between saidmotor and pump, means for delivering oilthrough certain of said pump andmotor bearings and into heat absorbing contact With the stator of saidmotor, and means for delivering oil through other of the pump and motorbearings and into heat absorbing contact with the rotor of said motor.

2. An apparatus comprising a casing, a pump,4

within said casing, an electric motor within said casing, a drivingconnection between said Lmotor and pump, means for delivering oilthrough cer- -tain of said pump and motor bearings and into heatabsorbing contact with the stator of said motor, means for deliveringoil through other of the pump and motor bearings and into heat absorbingcontact with the rotor of said motor, means for cooling all of the oilpassing over said motor, and thermostatically controlled means'f'orregulating the cooling of said oil.

4. An apparatus comprising a base, an electric motor, a pump, a drivingconnection between said motor and pump, an oil distributor above saidmotor, means for delivering oil from said pump to said distributorwhereby the same is distributed over said motor, a shield disposed inproximity to but spaced from said distributor for directing thedistributed oil into contact with the motor stator, a case associatedwith said base to provide a sealed enclosure within which said pump,motor, distributor andshield are disposed, means for dissipating heatremoved by said oil from the motor, thermostatically controlled means vfor regulating'the dissipation of heat from said oil, and a collectorassociated with said stator arranged to collect the oil distributed intocontactwith said motor stator and direct it over said thermostaticcontrol. v

5. An apparatus comprising a base, an electric motor, a pump, a drivingconnection between said motor and pump, an cil distributor, means fordelivering oil to said distributor whereby the same is distributed intocontact with the motor stator,

said stator being provided with passages through the interior to permitflow of the oil therethrough, a ca associated with said base to providea sealed enclosure within which said pump, motor and distributor aredisposed, means for dissipating heat removed by said oil from thestator, thermostatically controlled means for regulating the dissipationof heat from said oil, and

l a collector associated with said stator arranged to collect the oildistributed into contact withsaid motor so that it may return by gravityin intimate heat absorbing relation with the motor and back into thelower portion of said case, and means for collecting the portion of thedistributed fluid and directing it into contact with said therniostaticcontrol.

7. An apparatus comprising a hermetically sealed casing adapted tocontain lubricant, a pump and an electric motor disposed within saidcasing, means for directing lubricant from the pump into heat absorbingcontact with the motor to absorb excess heat units therefrom, alubricantt cooling device exteriorly of the casing, a connection throughwhich lubricant is delivered from the lower part of the casing to saiddevice, a connection through `which the cooled lubricant is deliveredfrom said device back to the pump, a thermostatically controlled by-passvalve through which lubricant may be delivered directly from the casingto the pump, and means for collecting lubricant heated by the motor anddirecting the same against said valve whereby the opening and closing ofthe valve is controlled by the temperature of said' collected lubricantto vary the amount of lubricant circulated through perature of theapparatus.

8. An apparatus comprising a sealed casing providing a lubricant sump, apump and a driving motor therefor located within the casing, means fordirecting lubricant delivered by the pumpinto heat absorbing contactWith the motor to cause the absorption of excess heat units from themotor by said lubricant, means comprising a closed lubricant circuitincluding a cooling device for cooling the lubricant whichis withdrawnthrough said circuit from the sump and returned to said pump, athermostatically controlled bypass v alve adapted to establish directcommunication between said sump and the suction side of said pump, andmeans for collecting the lubricant heated by said motor and directingthe same into thermal relation with said lthermostatic valveto therebyregulate the circulation of lubricant through said cooling device.

9. An apparatus comprising a casing providing an o'il sump, a pump andan electric motor within the casing, a driving connection between themotr and pump, means for directing oil delivered by the pump into heatabsorbing contact with the motor to cool the vmotor, a cooler forremoving from the oil the excess heat units absorbed from the motor, aconduit connecting the sumpto the inlet of the cooler, a conduitconnecting the'outlet of the cooler with the suction side said coolingdevice and thereby regulate the temof the pump, said suction conduitbeing provided with apart opening into the sump, and thermostaticallycontrolled means associated with said port for permitting a direct flowof oil from said sump to the suction side of said pump when thetemperature of said oil is below a predetermined minimum, said pumpbeing connected to circulate oil through said cooler when saidthermostatic means is closed.

10. An apparatus comprising a casing, a pump and an electric motordisposed therein, an oil cooler, a pipe for conducting oil from thecasing to the cooler, a pipe for conducting cooled oil from said coolerto the pump, a port for establishing communication between said casingand the pump intake through Which oil may be delivered directly from thecasing to the pump and a thermostatic valve controlling said port, saidvalve being influenced by the temperature of the oil ,in said casing topermit direct iioW of oil from the casing to the pump under lowtemperatures and to prevent such direct flow and cause flow through saidcooler under high temperatures, whereby the temperature of the oildelivered by the pump is regulated, and means for directing said oilinto heat absorbing Contact with said motor to cool the same.

11. In a refrigerating apparatus, the combination of a casing memberproviding a lubricant sump in the lower portion thereof, an electricmotor including a stator member and a rotor member mounted within saidcasing, a vertically disposed shaft supporting said rotor member, alubricant circulating pump driven by said shaft and having inlet andoutlet ports, means for dividing the lubricant under pump pressure intoa. plurality of streams, means for conducting all of the lubricantdischarged by the pump to an elevation above said motor from whichelevation both of said streams are separately returned under theinfluence of gravity to said sump, means for directing the lubricant ofone of said returning streams into heat transferring relation with oneof said members, independent means for directing the lubricant of theother of said returning streams into heat transferring relation withanother of said members, and means whereby heat units transferred fromthe motor to said lubricant may be delivered from the casing.

CARL E. L. LIPMAN.

